Publications

Pore-throat sizes in silidclastic rocks form a continuum from the submillimeter to the nanometer scale. That continuum is documented in this article using previously published data on the pore and pore-throat sizes of conventional reservoir rocks, tight-gas sandstones, and shales. For measures of central tendency (mean, mode, median), pore-throat sizes (diameters) are generally greater than 2 μm i

Audiomagnetotelluric (AMT) data along four profiles in western Snake Valley and the corresponding two-dimensional (2-D) inverse models reveal subsurface structures that may be significant to ground-water investigations in the area. The AMT method is a valuable tool for estimating the electrical resistivity of the earth over depth ranges from a few meters to less than one kilometer. The method has

No abstract available.

This study extends the application of local spatial nonparametric prediction models to the estimation of recoverable gas volumes in continuous-type gas plays to regimes where there is a single geologic trend. A transformation is presented, originally proposed by Tomczak, that offsets the distortions caused by the trend. This article reports on numerical experiments that compare predictive and clas

An unusually thick section of sedimentary breccias dominated by target-sediment clasts is a distinctive feature of the late Eocene Chesapeake Bay impact structure. A cored 1766-m-deep section recovered from the central part of this marine-target structure by the International Continental Scientific Drilling Program (ICDP)-U.S. Geological Survey (USGS) drilling project contains 678 m of these brecc

The U.S. Geological Survey (USGS) acquired two 1.4-km-long, high-resolution (~5 m vertical resolution) seismic-reflection lines in 2006 that cross near the International Continental Scientific Drilling Program (ICDP)–USGS Eyreville deep drilling site located above the late Eocene Chesapeake Bay impact structure in Virginia, USA. Five-meter spacing of seismic sources and geophones produced high-res

Human subjects decide when to sink a fixed cost C to seize an irreversible investment opportunity whose value V is governed by Brownian motion. The optimal policy is to invest when V first crosses a threshold V* = (1 + w*) C, where the wait option premium w* depends on drift, volatility, and expiration hazard parameters. Subjects in the Low w* treatment on average invest at values quite close to o

How the processes that initiate turbidity currents influence turbidite deposition is poorly understood, and many discussions in the literature rely on concepts that are overly simplistic. Marine geological studies provide information on the initiation and flow path of turbidity currents, including their response to gradient. In case studies of late Quaternary turbidites on the eastern Canadian and

A 443.9-m-thick, virtually undisturbed section of postimpact deposits in the Chesapeake Bay impact structure was recovered in the Eyreville A and C cores, Northampton County, Virginia, within the "moat" of the structure's central crater. Recovered sediments are mainly fine-grained marine siliciclastics, with the exception of Pleistocene sand, clay, and gravel. The lowest postimpact unit is the upp

This paper summarizes five 2007–2008 resource commodity committee reports prepared by the Energy Minerals Division (EMD) of the American Association of Petroleum Geologists. Current United States and global research and development activities related to gas hydrates, gas shales, geothermal resources, oil sands, and uranium resources are included in this review. These commodity reports were written

Seven previously unrecognized fusulinid species from Lower Permian (Wolfcampian and Leonardian) turbidites near Conglomerate Mesa in east-central California, four of which are named as new species, are here described and figured. The four new species are Schwagerina merriami, S. wildei, Parafusulina mackevetti, and Skinnerella rossi. These fusulinid species have close affinities to similar taxa in

Among the greatest uncertainties in future energy supply and a subject of considerable environmental concern is the amount of oil and gas yet to be found in the Arctic. By using a probabilistic geology-based methodology, the United States Geological Survey has assessed the area north of the Arctic Circle and concluded that about 30% of the world’s undiscovered gas and 13% of the world’s undiscover